29,830 research outputs found
Economic Potential of Substituting Legumes for Synthetic Nitrogen in Warm Season Perennial Grasses used for Stocker Cattle Grazing
No full textStocker cattle grazing warm season perennial grasses is an important economic activity in the southern Great Plains. Substantial increases in the price of nitrogen fertilizer is negatively affecting forage producers’ profitability. Two alternative nitrogen management systems that use annual and perennial legumes have been developed for bermudagrass pastures. The goal of the study is to determine if the legumes systems are more profitable than the conventional practice of applying synthetic sources of nitrogen. Results of the two-year grazing study show that the legume systems could not compete economically with the common practice.economics, grazing, legumes, bermudagrass, nitrogen fertilizer, stocker cattle, Crop Production/Industries, Farm Management, Production Economics,
Optimal Grazing Termination Date for Dual-Purpose Winter Wheat Production
No full textDual-purpose winter wheat (fall-winter forage plus grain) production is an important economic enterprise in the southern Great Plains. Grazing termination to enable grain production is a critical decision. The objective is to determine the optimal grazing termination date for dual-purpose wheat. The value of knowing the occurrence of first hollow stem (FHS), a wheat growth threshold for grazing termination, is also determined. Results indicate that for most price situations grazing should be terminated at or before FHS. Marginal wheat returns from extended grazing were negative and the value of FHS information ranges from 10 per acre.dual-purpose, first hollow stem, plateau function, stocker cattle, value of information, wheat, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Land Economics/Use, Livestock Production/Industries, Production Economics, Q12, Q16,
Ocean gyres and abrupt change in the thermohaline circulation: a conceptual analysis
No full textThe implications are investigated of representing ocean gyre circulations by a diffusion term in the Stommel and Rooth box models of the thermohaline circulation (THC) in one and two hemispheres, respectively. The approach includes mostly analytical solution and study of the bifurcation structure, but also numerical integration and feedback analysis. Sufficient diffusion (gyre strength) eliminates multiple equilibria from either model, highlighting the need for accurate gyre circulation strength in general circulation models (GCMs) when considering the potential for abrupt climate change associated with THC shutdown.With diffusion, steady-state flow strength in the Rooth model depends on freshwater forcing (i.e., implied atmospheric water vapor transport) in both hemispheres, not only on that in the upwelling hemisphere, as in the nondiffusive case. With asymmetric freshwater forcing, two solutions (strong stable and weak unstable) are found with sinking in the hemisphere with stronger forcing and one solution with sinking in the other hemisphere. Under increased freshwater forcing the two solutions in the hemisphere with stronger forcing meet in a saddle-node bifurcation (if diffusion is sufficiently strong to prevent a subcritical Hopf bifurcation first), followed by flow reversal. Thus, the bifurcation structure with respect to freshwater forcing of the diffusive Rooth model of two-hemisphere THC is similar to that of the Stommel model of single-hemisphere THC, albeit with a very different dynamical interpretation. Gyre circulations stabilize high-latitude sinking in the Stommel model. In the Rooth model, gyre circulations only stabilize high-latitude sinking if the freshwater forcing is weaker in the sinking hemisphere than in the upwelling hemisphere, by an amount that increases with diffusion. The values of diffusion and freshwater forcing at which qualitative change in behavior occurs correspond to the range of the values used in and obtained with GCMs, suggesting that this analysis can provide a conceptual foundation for analyzing the stability of the interhemispheric THC, and also for the potential of the Atlantic THC to undergo abrupt change
Servianorum in Vergilii carmina commentariorum Editio Harvardiana. Vol. III. The Commentaries on Aeneid III-V, éd. Stocker (Arthur F.) et Travis (Albert H.), avec la collab. de Smith (Howard T.), Waldrop (George B.) et Bruère (Richard T.)
No full textPréaux Jean. Servianorum in Vergilii carmina commentariorum Editio Harvardiana. Vol. III. The Commentaries on Aeneid III-V, éd. Stocker (Arthur F.) et Travis (Albert H.), avec la collab. de Smith (Howard T.), Waldrop (George B.) et Bruère (Richard T.). In: Revue belge de philologie et d'histoire, tome 44, fasc. 2, 1966. Histoire (depuis la fin de l'Antiquité) - Geschiedenis (sedert de Oudheid) pp. 595-598
Implanting Beef Calves and Stocker Cattle
No full text4 pp., 1 figure, 2 tablesImplanting beef calves offers one of the highest benefit-to-cost ratios of all the management practices available to cow/calf and stocker cattle producers. This publication offers advice on implant administration
Letter from Carl Hayden to Henry F. Ashurst
No full textLetter describing three enclosures, a letter from F. M. Gold, Carl T. Hayden's reply to Gold's letter, and a copy of a bill introduced by Cameron
Letter from A. F. Potter to Carl Hayden
No full textLetter from A. F. Potter to Carl T. Hayden describing John H. Page's request to build a railway for the Canyon Copper Company as "impractical"
E. K. Rand, J. J. Savage, H. T. Smith, G. B. Waldrop, J. P. Elder, Β· M. Peebles, A. F. Stocker. Seruianorum in Vergilíí Carmina Commentariorum Editionis Harvardianae volumen II (Commentaire sur l'Énéide I-II)
No full textvan de Woestijne Paul. E. K. Rand, J. J. Savage, H. T. Smith, G. B. Waldrop, J. P. Elder, Β· M. Peebles, A. F. Stocker. Seruianorum in Vergilíí Carmina Commentariorum Editionis Harvardianae volumen II (Commentaire sur l'Énéide I-II). In: L'antiquité classique, Tome 15, fasc. 2, 1946. pp. 337-339
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